Conductor cleaning system and method

ABSTRACT

A conductor cleaning system for cleaning aluminum strands of all aluminum and steel reinforced conductors, such as ACSS, ACSR, ACAR, and AAA. The conductor cleaning system having a container adapted to receive a portion of a conductor to be cleaned, a housing adapted to receive and support the container, and a cleaning solution contained in the container for cleaning the portion of the conductor. The cleaning solution being adapted to clean the conductor without reacting with or damaging the conductor.

This application is a Continuation-In-Part of U.S. patent applicationSer. No. 12/357,610 filed on Jan. 22, 2009.

BACKGROUND OF THE INVENTION

The present invention relates generally to a conductor cleaning system,and more particularly to a system for cleaning aluminum strands of allaluminum and steel reinforced electrical conductors, such as ACSS, ACSR,ACAR, and AAA.

In current power transmission systems, failures can pose a significantrisk to the reliability of the system. There are several factors thatcontribute to these failures—one such factor is the failure ofcompression connectors.

Current data suggests that a primary root cause for failures incompression connectors is improper installation. Examples of improperinstallation include lack of compound, alignment, wrong die, and poorcleaning of the aluminum strands of the conductor prior to installationof compression connectors. Research indicates that corrosion productsand other contaminants (resulting from years of exposure to theenvironment) left on the conductors during splice assembly can raise theresistance of the splice-conductor joint (this is also true of newconductors which have oxidation and contaminants thereon). Cyclicalvariations of load current feeding through the increased resistance ofthe splice-conductor joint causes thermal expansion/contraction thateventually reduces the grip of the splice to a point where it can nolonger hold the conductor.

Currently, compression connector installers clean the aluminum strandswith a wire brush, which results in ineffective cleaning of the strands,leaving corrosion products and other contaminants behind. Further, theinstaller cannot clean internal strands using the wire brush unless theinstaller takes the time to unstrand the conductor. Unfortunately,unstranding is impractical in most field conditions and can increase therisk of damage to the individual strands.

Accordingly, there is a need for a conductor cleaning system that caneffectively clean both outer and inner strands of a conductor withoutthe need to unstrand the conductor.

BRIEF SUMMARY OF THE INVENTION

These and other shortcomings of the prior art are addressed by thepresent invention, which provides a conductor cleaning system capable ofcleaning external and internal strands of a conductor withoutunstranding the conductor.

According to one aspect of the present invention, a conductor cleaningsystem includes a container adapted to receive a portion of a conductorto be cleaned, a housing adapted to receive and support the container,and a cleaning solution contained in the container for cleaning theportion of the conductor. The cleaning solution is adapted to clean theconductor without reacting with or damaging the conductor.

According to another aspect of the present invention, a cleaningsolution adapted to clean electrical conductors without damaginggalvanization coatings or degrading aluminum contained in the coatingsor conductor has a composition, by approximate weight percent, of 0.985to 8.97 NaOH, 0.49 to 1.45 NaF, and 89.7 to 98.5 H₂O

According to another aspect of the present invention, a method ofcleaning an electrical conductor includes providing a conductor cleaningsystem having a container and an agitator. The method further includesproviding a cleaning solution for cleaning of the electrical conductor,introducing the cleaning solution into the container, positioning anelectrical conductor in the cleaning solution disposed in the container,and activating the agitator, thereby agitating the cleaning solution andenhancing its ability to clean the electrical conductor.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter that is regarded as the invention may be bestunderstood by reference to the following description taken inconjunction with the accompanying drawing figures in which:

FIG. 1 is a perspective view of a conductor cleaning system according toan embodiment of the invention;

FIG. 2 shows a vibrator housing of the conductor cleaning system of FIG.1;

FIG. 3 shows an eccentric weight for use in a vibrator of the conductorcleaning system of FIG. 1;

FIG. 4 shows a battery and receptacle for the conductor cleaning systemof FIG. 1;

FIG. 5 shows a control panel for the conductor cleaning system of FIG.1;

FIG. 6 shows the conductor cleaning system of FIG. 1 being carried;

FIG. 7 shows the conductor cleaning system of FIG. 1 in use;

FIGS. 8-10 show the conductor cleaning system of FIG. 1 supported in anupright position by supports;

FIG. 11 shows the conductor cleaning system of FIG. 1 fitted withbi-pods;

FIG. 12 shows a tri-pod for supporting the conductor cleaning system ofFIG. 1;

FIG. 13 is a perspective view of a conductor cleaning system accordingto an embodiment of the invention; and

FIG. 14 is a graph showing pH v. cleaning sequence.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings, an exemplary conductor cleaning systemaccording to the present invention is illustrated in FIG. 1 and showngenerally at reference numeral 10. The system 10 includes a container,such as tube 11 operably connected to an agitator, such as vibrator 12,FIG. 2, contained in a vibrator housing 13, and a control panel 14 forcontrolling the system 10. The container 11 may be disposable orpermanently attached to the system 10.

The vibrator housing 13 is adapted to receive and support the container11, and includes an attachment rail 16 to allow the system 10 to beattached to a support for easy operation or to allow a user to easilycarry the system 10. Other attachments such as a hook-type attachmentmay also be used to attach the system 10 to a bucket of a bucket truckor other suitable support. A standing base 17 is disposed at one end ofthe housing 13 to allow the system 10 to be positioned in a stand-upposition such that the tube 11 is in a vertical position. The base 17may be adapted to accept supports to further stabilize the system 10 inthe vertical position, as shown in FIGS. 8-10. Guide straps 18 and 19are attached to opposing ends 20 and 21 of the housing 13 to provideguides and supports for the tube 11, and a retaining strap 22 ispositioned between the guide straps 18 and 19 to lock the tube 11 intoposition. A support 23 is also positioned on a bottom of the housing 13to further position and lock the tube 11 into position. As shown, thesupport 23 is V-shaped; however, any suitable geometry may be used toposition and lock the tube 11 in position.

As shown in FIG. 2, the vibrator housing 13 includes a control system 30having an electric motor 31, a timer circuit 32, a voltage regulator 33,and the vibrator 12. The vibrator 12 includes an eccentric weight 15,like that shown in FIG. 3, to emit vibrations into the tube 11, therebyagitating a cleaning solution contained therein. While a vibrator isbeing described herein, it should be appreciated that other types ofagitators may be used, for example, ultrasonic, bubbling air, andstirring. Together, the motor 31 and vibrator 12 cause the system 10 tovibrate at a specified rate by spinning the eccentric weight 15 at adesired speed. It should be appreciated that the speed of the motor 31and size of the eccentric weight 15 may be changed to optimize theconductor cleaning efficiency. It should be appreciated that other formsof vibrators/agitators may be used, such as ultrasonic.

Referring to FIG. 4, the system 10 is powered by a battery 36. Thebattery 36 is contained in a battery receptacle 37 of the base 17. Thebattery 36 may be replaceable or rechargeable and allows the system 10to be portable for conductor cleaning both at ground level and atelevated levels.

As illustrated in FIG. 5, the control panel 14 is electrically connectedto the control system 30 and includes a power switch 38, a timer 39, astart button 40, and a buzzer 41. The power switch 38 turns the system10 on to a ready state so that the system 10 is ready to clean aconductor. The timer 39 allows a user to choose how long the cleaningprocess is going to last. The amount of time chosen is dependent on thelevel of contaminants and corrosion products on the surface of theconductor, temperatures, and other factors. The start button 40 turnsthe cleaning process on when depressed, and the buzzer 41 lets a userknow when the cleaning process has ended.

The cleaning solution is contained in the tube 11 to allow an end of aconductor to be cleaned properly while reducing spills and splashes. Thecleaning solution is designed and optimized to permit cleaning ofaluminum strands of conductors without unstranding the conductor.Namely, the cleaning solution is designed to permit internal andexternal cleaning of aluminum strands of the conductor without reactingand damaging the galvanization of galvanized steel strands; to not reactwith or degrade aluminum strands after the cleaning process is complete;to clean over a wide range of temperatures; to not react with inhibitorcompounds used in compression connector installation; and to beenvironmentally acceptable.

The cleaning solution uses a caustic solution of sodium hydroxide (NaOH)as a cleaning agent due to the tri-hydrated oxide of aluminum found incorrosion products being soluble in this type of solution. It should beappreciated that other suitable caustic hydroxides may be used. Thecaustic level of the solution is equal to, or less than, that ofstandard household cleaners. A low concentration of sodium fluoride(NaF) enhances the solubility of the aluminum oxides and reduces thetime needed to complete the cleaning. The predominant reactionsoccurring during cleaning are as follows:

Al₂O₃+2NaOH

2NaAlO₂+H₂O

2Al+2NaOH+2H₂O→2NaAlO₃+3H₂.

The reaction products are essentially stable and do not react with Aland the corrosion layer Al₂O₃. Only NaOH chemically attacks both Al andAl₂O₃. Examples of cleaning solutions are shown in the Table below.

Solution No. Composition Caustic Level 1 NaOH + H₂O High 2 NaOH +NaPO₄•12H₂O + NaF + Medium H₂O 3 NaOH + NaPO₄•12H₂O + NaF + Medium-LowH₂O 4 NaOH + NaF + H₂O Low

In testing, all of the above solutions provided good to excellentcleaning results. For example, in one test, a cleaning solution having alow level of causticity and relatively simple composition was chosen.The cleaning solution had the following concentrations:

Sodium Hydroxide (NaOH)=20 g (approx. weight percent=1.93)

Sodium Fluoride (NaF)=15 g (approx. weight percent=1.45)

Water (H₂O)=1 L. (approx. weight percent=96.62)

It should be appreciated that other concentrations could be useddepending on the application. For example, it was found that solutionshaving approximate weight percent ranges of 0.985 to 8.97 NaOH, 0.49 to1.45 NaF, and 89.7 to 98.5H₂O were acceptable. The chemicals were mixedin the water until completely dissolved. It was determined that thelevel of cleaning and the time to achieve that level were dependent onthe solution temperature and the amount of agitation provided to thesolution by the vibrator 12. This can be seen in the table below.

Temper- Cleaning Effectiveness Rated 0 to 5 with 5 Being the Best atureWith Agitation Without Agitation (C.) 1 Min 2.5 Min 5 Min 1 Min 2.5 Min5 Min 0 3 4 4 1 1 2 25 4 5 5 2 3 4 50 5 5 5 5 5 5 70 5 5 5 5 5 5It should be appreciated that other forms of agitation may be used, suchas ultrasonic, bubbling air, stirring, etc.

When using a cleaning solution with ACSS and other conductors havingaluminum incorporated into the steel core's zinc coating, care must betaken to prevent damaging the aluminum in the Al—Zn coating thatprotects the steel strands of the electrical conductor. The Al—Zncoating protects the steel strands from corrosion and degradation of thecoating would be detrimental to the life of the electrical conductor. Asa result, it was determined that the use of an inhibitor in the cleaningsolution would be beneficial.

It was found that an inhibitor such as sodium silicate(Na₂O(SiO₂)_(x)(H₂O)_(x)) protected the Al—Zn coating while allowing thecleaning solution to adequately clean the electrical conductor. It wasfurther found that a approximate weight percent range of 0.15 to 1.42 ofsodium silicate was acceptable. When mixing the sodium silicate with thecleaning solution it was found that a solution, by approximate weightpercent, of (0.15 to 1.42) Na₂O(SiO₂)_(x)(H₂O)_(x)+(1.90 to 1.93)NaOH+(1.43 to 1.45)NaF+(95.24 to 96.47) H₂O adequately cleaned theelectrical conductors and protected the Al—Zn coating.

In addition to preventing damage to the Al in the Al—Zn coating, the pHis a concern due to EPA regulations for handling chemical solutions.Thus, it is beneficial to maintain the cleaning solution below a pH of12.5. It was found, that various chemicals could be used to lower the pHof the solution. For example, it was found that a CaCl₂ solution couldlower the pH from 13.0 to 12.4. However, the CaCl₂ solution tends toleave a residue.

It was further found that the use of ascorbic acid provided manybenefits that the other chemicals did not. For example, the ascorbicacid was beneficial for both lowering the pH and for protecting theAl—Zn coating. An acceptable range, by approximate weight percent, ofascorbic acid was found to be 0.193 to 3.54. This results in a cleaningsolution having a composition, by approximate weight percent, of (0.193to 3.54) ascorbic acid+(1.87 to 1.93) NaOH+(1.40 to 1.45)NaF+(93.28 to96.43) H₂O.

In addition to lowering the pH and protecting the Al—Zn coating, whenusing the ascorbic acid, it was unexpectedly found that after a certainnumber of cleanings the pH of the cleaning solution dramatically felloff (See FIG. 14), thereby indicating the need to change the cleaningsolution before cleaning any more conductors. This is extremelybeneficial because by simply monitoring the pH of the solution, a userknows exactly when to change out the solution for optimum cleaning.

As can be seen from FIG. 14, a cleaning solution without ascorbic acidmaintains a fairly constant pH across the cleaning sequences. On theother hand, the ascorbic modified cleaning solution steadily decreasesin pH until the cleaning solution becomes ineffective (indicated by thesudden drop off in pH). As such, a user cleaning multiple conductors canmonitor the pH of the ascorbic modified solution and easily determine anormal range of drop in pH either visually by graphing pH measurementsprior to and after each cleaning, as done in FIG. 14, or by calculatingthe drop in pH for each cleaning using the pH measurements and thendetermining a normal range of drop in pH. If during a cleaning, a dropin pH of the cleaning solution exceeds the normal range, then the userknows to dispose of the spent cleaning solution and replace it with newcleaning solution.

In use, the tube 11 is inserted through the guide straps 18 and 19 ofthe vibrator housing 13 and secured in position by the retaining strap22 and support 23. As discussed, the tube 11 may be disposable orpermanently attached to the system 10. In the case of a disposable tube,the tube 11 may be pre-filled with the cleaning solution and a plug 42would be inserted into an end of the tube 11 to prevent spilling of thesolution. The tube would then be attached to the system 10 and carried,as shown in FIG. 6, to the conductor cleaning site. After use, the tube11 would be removed from the system 10 and the tube and cleaningsolution would be properly disposed of.

In the case of a permanent tube, the tube 11 would be attached to thesystem 10 and carried to the conductor cleaning site. The cleaningsolution could be poured into the tube 11 and sealed therein by the plug42 prior to delivery to the cleaning site, could be delivered to thesite in another container and then poured into the tube at the site, orcould be in powder form which would be mixed with water at the site.

Referring to FIG. 7, once at the conductor cleaning site, a conductor 43is inserted into the tube 11 so that the cleaning solution containedtherein may clean the strands of the conductor 43. A baffle 44 may beinserted into the end of the tube 11 to prevent splashing during thecleaning process. With the conductor 43 positioned in the cleaningsolution, the power switch 38 is moved to the on position and the timer39 is moved to a desired time limit. The duration of vibration isdetermined by the user depending on the present temperature and theamount of deposits on the conductor surfaces. The start button 40 isthen depressed and the motor rotates the eccentric weight 15 of thevibrator 12, thereby causing vibrations to agitate the cleaning solutionto ensure that internal and external strands of the conductor arecleaned.

As discussed, during the cleaning cycle of the conductor, the system 10may be supported in various ways to relieve the burden, on the user, ofsupporting the system 10. For example, if the system is to be supportedin a vertical position, supports may be attached to the base 17, FIGS.8-10. As shown in FIG. 8, legs 46 are directly attached to the base 17.Legs 46 may be secured to the base 17 using fasteners. As illustrated inFIG. 9, removable legs 47 are secured to the base 17 by pins 48. Thisallows the legs 47 to be removed when supporting the system 10 in avertical position is not necessary. As shown in FIG. 10, foldable legs50 are secured to the base 17 by supports 49 which allow the legs 50 topivot between a use position and a non-use position about pin 51.

Other support methods may also be employed. For example, in FIG. 11, abi-pod having legs 53 and 54 may be attached to strap 18. The legs 53and 54 may be moved between a use position and a non-use position toallow the system 10 to be supported in a non-vertical position. As shownin FIG. 12, a tri-pod 60 may also be used to support the system 10. Asshown, the tri-pod 60 includes adjustable legs 61, 62, and 63 to allowfor adjustment on uneven surfaces. The system 10 is then hung from thetri-pod 60 using the attachment rail 16.

Referring to FIG. 13, a conductor cleaning system 110 is shown. Likesystem 10, system 110 includes a container 111 operably connected to avibrator contained in a vibrator housing 113, a control panel 114, anattachment rail 116, a base 117, and retaining straps 118, 119, and 122.Unlike system 10, the container 111 of system 110 is a trough-likecontainer to allow cleaning of a conductor 143 at a point intermediaryof opposing ends of the conductor 143 without cutting. This allows theconductor 143 to be cleaned at locations where compression fittings,such as repair sleeves and T-connections, are being installed along theconductor 143.

In use, the container 111 is positioned at a point along the conductor143 where cleaning is desired and moved into engagement with theconductor 143. Seals 160 and 161 permit the conductor 143 to be pressedinto the container 111 until the conductor 143 is immersed in thecleaning solution. The seals 160 and 161 prevent the cleaning solutionfrom leaking between the container 111 and the conductor 143.

The foregoing has described a conductor cleaning system. While specificembodiments of the present invention have been described, it will beapparent to those skilled in the art that various modifications theretocan be made without departing from the spirit and scope of theinvention. Accordingly, the foregoing description of the preferredembodiment of the invention and the best mode for practicing theinvention are provided for the purpose of illustration only and not forthe purpose of limitation.

We claim:

1. A cleaning solution adapted to clean electrical conductors,comprising: a caustic composition including a hydroxide cleaning agent.2. The cleaning solution according to claim 1, wherein the hydroxidecleaning agent is sodium hydroxide (NaOH).
 3. The cleaning solutionaccording to claim 1, wherein the caustic composition, by approximateweight percent, comprises 0.985 to 8.97 NaOH.
 4. The cleaning solutionaccording to claim 1, wherein the caustic composition further includesNaF to enhance the solubility of aluminum oxides and reduce the timeneeded to complete a cleaning of an electrical conductor.
 5. Thecleaning solution according to claim 1, wherein the caustic composition,by approximate weight percent, comprises 0.49 to 1.45 NaF.
 6. A cleaningsolution adapted to clean electrical conductors without damaginggalvanization coatings or degrading aluminum contained in the coatingsor conductor, the cleaning solution having a composition comprising, byapproximate weight percent, 0.985 to 8.97 NaOH, 0.49 to 1.45 NaF, and89.7 to 98.5H₂O.
 7. The cleaning solution according to claim 6, furtherincluding, by approximate weight percent, 0.15 to 1.42Na₂O(SiO₂)_(x)(H2O)_(x).
 8. The cleaning solution according to claim 7,wherein the cleaning solution comprises, by approximate weight percent,0.15 to 1.42 Na₂O(SiO₂)_(x)(H2O)_(x), 1.90 to 1.93 NaOH, 1.43 to 1.45NaF, 95.24 to 96.47H₂O.
 9. The cleaning solution according to claim 6,further including, by approximate weight percent, 0.193 to 3.54 ascorbicacid.
 10. The cleaning solution according to claim 9, wherein thecleaning solution comprises, by approximate weight percent, 0.193 to3.54 ascorbic acid, 1.87 to 1.93 NaOH, 1.40 to 1.45 NaF, 93.28 to96.43H₂O.
 11. The cleaning solution according to claim 6, furtherincluding an inhibitor to prevent degradation of aluminum in thegalvanization coatings or the conductor.
 12. The cleaning solutionaccording to claim 6, further including an acid to control pH of thecleaning solution such that the pH is maintained below 12.5.
 13. Amethod of cleaning an electrical conductor, comprising: (a) providing aconductor cleaning system having: (i) a container; and (ii) an agitator;(b) providing a cleaning solution for cleaning of the electricalconductor; (c) introducing the cleaning solution into the container; (d)positioning an electrical conductor in the cleaning solution disposed inthe container; and (e) activating the agitator, thereby agitating thecleaning solution and enhancing its ability to clean the electricalconductor.
 14. The method according to claim 13, wherein the cleaningsolution comprises, by approximate weight percent, 0.15 to 1.42Na₂O(SiO₂)_(x)(H2O)_(x), 1.90 to 1.93 NaOH, 1.43 to 1.45 NaF, 95.24 to96.47H₂O.
 15. The method according to claim 13, wherein the cleaningsolution comprises, by approximate weight percent, 0.193 to 3.54ascorbic acid, 1.87 to 1.93 NaOH, 1.40 to 1.45 NaF, 93.28 to 96.43H₂O.16. The method according to claim 13, further including the step ofchecking the pH of the cleaning solution before and after cleaning theelectrical conductor.
 17. The method according to claim 16, furtherincluding the step of replacing the cleaning solution with a newcleaning solution when the pH of the cleaning solution indicates thatthe cleaning solution is ineffective in cleaning the electricalconductor.
 18. A method of determining when to replace a cleaningsolution in a conductor cleaning system with a new cleaning solution,comprising: (a) measuring a pH of the cleaning solution prior to andafter each cleaning of multiple electrical conductors; (b) calculating adrop in pH of the cleaning solution for each cleaning using the pHmeasurements taken prior to and after each cleaning of the electricalconductors; (c) determining a range of drop in pH using the calculateddrops in pH for each cleaning; and (d) replacing the cleaning solutionwith the new cleaning solution when a calculated drop in pH exceeds thedetermined range of drop in pH.